Continuous solvent dyeing process

ABSTRACT

Fabric, preferably polyester fabric, dyed in any appropriate manner with a non-reactive dyestuff is introduced while cool into a first chamber filled with saturated solvent vapors, the wet fabric is then passed to another chamber filled with super-heated vapors of the same solvent which permits the solvent to penetrate the fibers and carry the dye into the surface of the fibers.

United States Patent I 1111 3,762,872

Acree 1 Oct. 2,, 1973 [54] CONTINUOUS SOLVENT DYEING PROCESS 3,667,898 6/1972 Bergman et al 3/94 3,510,243 5 I970 t t l 9 [75] Inventor: William L. Acree, Greensboro, N.C. Seure e a 8/3 [73] Assignee: Burlington Industries, Inc., Primary Examiner-Leon D, Rosdol Greensboro, NC. Assistant Examiner-T. 1. Herbert, Jr.

[22] Filed: y 7, 1971 An0rneyCushman, Darby & Cushman [21] Appl. No.: 160,423 57 T C Fabric, preferably polyester fabric. dyed in any appro- [52] U.S. Cl 8/176, 8/94, 8/174 priate manner with a non-reactive dyestuff is intro- [51] Int. Cl. D06p 3/52, D06p 3/54 duced while cool into a first chamber filled with satu- [58] Field of Search 8/174, 94, 176 ated solvent apors, the wet fabric is then passed to another chamber filled with super-heated vapors of the [56] References Cited same solvent which permits the solvent to penetrate the UNITED STATES PATENTS fibers and carry the dye into the surface of the fibers.

2,999,002 9/l96l Dayvault ct al 8/94 15 Claims, 1 Drawing Figure co/vaavswa 60/45 /24 jfi r OVE/V Sift/0 1'50 504 nsvvr 30. 5;? l 6 6/7750 zz 50L V/VT SCOUA? PATENTED Um 21975 INVENTOR M4 z. lfl/ l L .A CF55 MMAWMW m ATTQRNEYS CONTINUOUS SOLVENT DYEING PROCESS The present process relates to the dyeing of fabrics, more especially fabrics containing polyester fibers.

It is well known that most nonreactive dyes require a heat fixation step during the dyeing cycle, usually at temperatures higher than necessary for either application of the dye or drying of the fabric.

In the present invention fibers, e.g. in the form of fabric preferably polyester fabric, which has been padded with non-reactive dye from aqueous or organic solvent bath or has had dye applied by another means, e.g. spraying, printing, coating, contact transfer, etc. are first dried, then cooled, preferably to from room temperature, e.g. about 68 to 100F. Usually the cooling is from 80 to 100F. Any method of cooling the fabric can be employed. There can also be employed dry fabric at room temperature to which dyestuff has been previously applied. Application of the dye can be at a temperature from 32F. up to 212F. or if no water is involved up to 250F.

The cooled fabric then enters a special fixation unit. On entering the unit the fabric is first passed into a chamber filled with saturated solvent vapors at the boiling point of the solvent. Due to the cooling effect of the fabric, solvent is condensed on the fibers and acts as the dyeing medium. The dye migrates somewhat and there is obtained the desirable property of leveling.

While the preferred solvent is perchloroethylene there can be employed other halohydrocarbons such as 1,1,1-trichloroethane, trichlorofluoromethane, carbon tetrachloride, chloroform, dichloromethane, 1,1,1- trichloro-2,2,2-trifluoroethane, 1,1,2-trichloro-1,2,2- trifluoroethane, pentachlorofluoroethane, 1 ,1,1,2- tetrachloroethane, 1,1,1 ,2-tetrachloro-2,2- difluoroethane, 1,1,2,2-tetrachloro-1,2-difluoroethane, pentachloroethane, pentachlorofluoroethane, trichloroethylene, 1,1-dichloroethylene, 1,2- dichloroethylene, 1,1,2-trichloroethane, l ,1 dichloroethane, ethylene chloride, hexafluorobenzene, chloropentafluorobenzene, benzotrifluoride, 1,1,2- trichloro-3 ,3 ,3-trifluoropropene-l chlorobenzene, ethylene dibromide, 1,1-dichloropropane, 1,1 ,2,2- tetrachloroethane, trimethylene dibromide, pentamethylene dibromide, o-dichlorobenzene, fluorobenzene, bromobenzene, o-bromotoluene, rn bromotoluene, p-bromotoluene, o-chlorotoluene, mchlorotoluene, p-chlorotoluene, trichlorobenzene, 1,2,4-trifluorobenzene, perfluoroheptane, perfluoro (2,2,4-trimentyl)pentane perfluorohexane, chlorocyclohexane, bromocyclohexane, 1,2-dibromocyelohexane and 1,2- dichlorocyclohexane. Of course mixtures of solvents can be used.

The wet fabric is then passed into a chamber where the same type vapor as that in the first chamber is heated, e.g. super-heated, to the desired temperature for dyeing. The temperature of the solvent vapors in the second chamber can be from the boiling point of the solvent up to 450F. Usually temperatures of 280370F. are preferred and there is no need to go up to 400F., e.g. it is rarely desirable to go above 350F.

To supply the extra heat required for the vapors in the second chamber they are pulled out and passed through a heat exchanger.

Due to the presence of the solvent vapor as the heat transfer medium in the second chamber it decreases the evaporating rate of the solvent from the fabric until the fabric reaches the boiling point of the solvent. This gives time for the solvent to penetrate the fibers and carry the dye into the surface of the fibers. When the fabric temperature reaches the boiling point of the solvent the solvent is evaporated but the absorbed solvent is still held by the fibers and aids in the penetration of the dye from the surface into the core of the fiber. As the temperature of the fabric increases to the temperature of the super-heated solvent the dye migrates into the center of the fibers producing a satisfactory dyeing which is fully penetrated. This step can be described as dye fixation. 1n the dye fixation as well as in the dye application step there is no need to use pressure and the chambers can be open to the atmosphere.

While the process is preferably employed with poly ester fabrics, e.g. polyethylene terephthalate (such as Dacron), polyethylene isophthalate terephthalate, and polycyclohexane dimethyl terephthalate (Kodel) it can be used with mixed fabrics such as Dacron-cotton (e.g. 65:35 or 35:65). It also can be employed with other fabrics such as nylon, acrylics, e.g. acrylonitrile polymers, e.g. 93 percent acrylonitrile 7 percent vinyl acetate or even cellulosics such as cellulose acetate (about 2 acetyl groups per glucose unit) or cellulose triacetate.

While the use of the present process with polyester fabrics permits more color yield and complete penetration of the fibers, the process with cellulose acetate and triacetate fibers and fabrics permits dyeing at a higher rate of speed than is otherwise possible.

Any of the conventional non-reactive dyestuffs can be used such as members of the classes of disperse, cationic, acid and pre-metallized acid as well as special dyes modified for solvent dyeing.

Examples of suitable dyestuffs are those mentioned in Chapman U.S. Pat. No. 3,034,847, e.g. 3-nitro-N- phenyl sulfanilanilide, p-[p-( Phenylazo) phenylazo] phenol, ethyl 4-hydroxy-1-anthraquinonecarbamate, l-amino-4-hydroxy-Z-methoxyanthraquinone, 1- amino-2-bromo-4-hydroxyanthraquinone, 1-(2- hydroxyethylamino)-4-methylaminoanthraquinone, l,4-diamino-N-(2-hydroxyethyl)-2,3-anthraquinonodicarboximide, 4,5-diaminochrysazine and l-anilino-4- hydroxyanthraquinone as well as others such as those shown in Goodings U.S. Pat. No. 3,082,053, e.g. Dispersol Fast Scarlet B. Duranol B, Dispersol Fast Scarlet A, methylene blue ZBNS and naphthalene green 65., the dyestuffs mentioned in Hirshfeld U.S. Pat. No. 3,4- 20,616, e.g C.l. Disperse Blue 71, C.l. Basic Red 30,

C.l. Acid Blue 25 C.l. 62055, C.l. Direct Yellow 50 C.l.

29025, C.l. Direct Red 30 C.l. 35780, C.l. Direct Blue 76 C.l. 24410, C.l. Basic Orange 24, C.l. Basic Blue 54, C.l. Basic Red 22, C.l. Disperse Blue 62, C.l. Acid Blue 80 C.l. 61585, C.l. Basic Red 18, C.l. Direct Yellow 28 C.l. 19155, C.l. Disperse Red 59, any of the dyestuffs set forth in Seuret U.S. Pat. No. 3,510,243, e.g. the dyestuffs set forth in examples 121 thereof; the cellulose acetate dyes set forth in Olpin U.S. Pat. Nos. 2,514,410 and 2,615,781, the dyes in Sertorio U.S. Pat. No. 2,828,180 as well as any on the non-reactive dyestuffs set forth in the Encyclopedia of Polymer Science and Technology Vol. 5 pages 235405, especially pages 376-405 (1966).

The invention will be understood best in connection with the drawings wherein:

The single FIGURE of the drawings is a schematic illustration of one form of suitable apparatus.

Referring more specifically to the drawings, polyethylene terephthalate fabric 2 from roll 4 has dyestuff applied by padding at 6, dried by any suitable means such as by passing through oven 8, then cooled on can 10. After cooling, the fabric enters into a first chamber 12 containing solvent, e.g., perchloroethylene. The solvent is boiling at the sump of the chamber and vapors of the solvent at the boiling point fill the space 16 to the indicated level; perchloroethylene has a vapor density greater than the air which occupies the space above the vapors. Condensation of the solvent on the fabric takes place to form the dye bath. Fabric is then passed into the second chamber 18 containing in the space 20 super heated vapors of the same solvent present in the first chamber. Condensing coils 34 and 36 are provided in the spaces in the chambers 12 and 18 above the solvent vapor levels and condensate returned to the boilers through lines 38 and 40. In chamber 18 solvent,

e.g., perchloroethylene boiling at the sump of the chamber passes through a heat exchanger (not shown) where it is superheated prior to entering space containing vapors 20. The dye fixation takes place in the chamber 18. The fabric is then solvent scoured in scourer 26 with any conventional scouring agent, usually with the same solvent as employed in chambers 12 and 18 to remove excess dye. The scouring liquid collects as a pool 28 and can be drawn off and recovered. Next the fabric 2 is dried, e.g., in oven 30 and wound on roll 32. The drying oven can be at any convenient temperature, e.g., 65 to 300F., but usually is above the boiling point of the solvent employed.

Unless otherwise indicated all parts and percentages are by weight.

EXAMPLE 1 A 6 ounce per square yard polyester (polyethylene terephthalate) fabric was padded with a 1 percent aqueous dispersion of C.l. Disperse Blue 56 to obtain a total wet pick-up of about 50 percent. The fabric was then dried in an oven. e.g. at 212F. and cooled to room temperature. The fabric with the dye applied was entered into a saturated atmosphere of perchloroethylene at its boiling point and kept there for seconds. Enough of the perchloroethylene condensed on the fabric to form the dyeing medium. The cloth was then passed into a chamber of superheated perchloroethylene at 3 lOF. for 90 seconds to penetrate the dye into the fibers and fix the dye. The fabric was then scoured with perchloroethylene and dried, e.g. at 250F.

EXAMPLE 2 Two grams of Cl. Disperse Red 135 were dissolved in 200 cc. of 1,1,l-trichloroethane. A [00 percent polyester fabric (polyethylene terephthalate) was padded through this solution with a total wet pick-up of about 60 percent. The fabric was then dried, e.g. at 200F., and cooled to room temperature. This fabric with the dye applied was passed through saturated perchloroethylene vapors at about 250F. for 10 seconds and then into super-heated perchloroethylene vapors at 310F. for 96 seconds after which it was scoured by perchloroethylene at room temperature and dried, eg. at 250F.

EXAMPLE 3 v A fabric of polyamide fibers (6,6 nylon) was padded with 1 percent C.l. Disperse Yellow 34 from an aqueous bath to give a pick-up of 50 percent. The fabric was then dried, e.g. at 212F. and cooled to room temperature before entering into a saturated atmosphere of perchloroethylene at 250F. for 10 seconds. From the saturated atmosphere the fabric was passed into a super-heated atmosphere of perchloroethylene at 260F. for 60 seconds, then scoured in perchloroethylene to remove excess dye, and dried, eg at 250F.

What is claimed is:

l. A process of fixing a non-reactive dye to a fabric consisting of passing cool dry fabric having a nonreactive dye applied thereto through vapors of a solvent at the boiling point, condensing the solvent on the fabric due to the cooling effect of the fabric and (2) immediately passing the fabric through vapors of a solvent at a temperature at least as high as the boiling point of the solvent to obtain fixation of the dye on the fabric.

2. A process according to claim 1 wherein the solvent in both steps (I) and (2) is the same and is a chlorinated hydrocarbon.

3. A process according to claim 2 wherein the fabric remains in contact with the solvent in step (2) until the fabric reaches the boiling point of the solvent.

4. A process according to claim 3 wherein the vapors of the solvent in step (2) are super-heated and are above the boiling point of the solvent.

5. A process according to claim 4 wherein the solvent is perchloroethylene.

6. A process according to claim 5 wherein the fabric is a polyester fabric.

7. A process according to claim 4 wherein the fabric is a polyester fabric.

8. A process according to claim 2 wherein the fabric is a polyester fabric.

9. In a process for the solvent dyeing of fabrics with a non-reactive dye the improvement consisting of carrying out the dyeing in two steps in immediate succession wherein in the first step the dye containing fabric is subjected to saturated vapors of a halogenated hydrocarbon at the boiling point and condensation of the solvent provides the dyebath and in the second step the dye containing fabric is subjected to superheated vapors of said halohydrocarbon for a time sufficient for the fabric to approximate the temperature of said super heated vapors and to fix the dye.

10. A process according to claim 9 wherein the fabric is a polyester.

11. A process according to claim 1 wherein the dye is a disperse dye.

12. A process according to claim 1 wherein the fabric is seiected from the group consisting of polyester fabrics, nylon fabrics, acrylic fabrics and cellulosic fabrics.

13. A process according to claim 12 wherein the dye is selected from the group consisting of disperse dyes, cationic dyes, acid dyes and pre-metallized acid dyes.

14. A process according to claim 13 wherein the dye is a disperse dye.

15. A process according to claim 13 wherein the vapors of the solvent in step (2) are super-heated and are above the boiling point of the solvent. 

2. A process according to claim 1 wherein the solvent in both steps (1) and (2) is the same and is a chlorinated hydrocarbon.
 3. A process according to claim 2 wherein the fabric remains in contact with the solvent in step (2) until the fabric reaches the boiling point of the solvent.
 4. A process according to claim 3 wherein the vapors of the solvent in step (2) are super-heated and are above the boiling point of the solvent.
 5. A process according to claim 4 wherein the solvent is perchloroethylene.
 6. A process according to claim 5 wherein the fabric is a polyester fabric.
 7. A process according to claim 4 wherein the fabric is a polyester fabric.
 8. A process according to claim 2 wherein the fabric is a polyester fabric.
 9. In a process for the solvent dyeing of fabrics with a non-reactive dye the improvement consisting of carrying out the dyeing in two steps in immediate succession wherein in the first step the dye containing fabric is subjected to saturated vapors of a halogenated hydrocarbon at the boiling point and condensation of the solvent provides the dyebath and in the second step the dye containing fabric is subjected to superheated vapors of said halohydrocarbon for a time sufficient for the fabric to approximate the temperature of said super heated vapors and to fix the dye.
 10. A process according to claim 9 wherein the fabric is a polyester.
 11. A process according to claim 1 wherein the dye is a disperse dye.
 12. A process according to claim 1 wherein the fabric is selected from the group consisting of polyester fabrics, nylon fabrics, acrylic fabrics and cellulosic fabrics.
 13. A process according to claim 12 wherein the dye is selected from the group consisting of disperse dyes, cationic dyes, acid dyes and pre-metallized acid dyes.
 14. A process according to claim 13 wherein the dye is a disperse dye.
 15. A process according to claim 13 wherein the vapors of the solvent in step (2) are super-heated and are above the boiling point of the solvent. 